Dampening device for a ball games racket

ABSTRACT

The present invention relates to a dampening device for a ball game racket, in particular a tennis, squash, racket ball or badminton racket, as well as to a ball game racket comprising a dampening device of this kind. The dampening device according to the invention comprises a base body made of foam material and a connecting means which is configured such that the dampening device can be fixed to at least one longitudinal string, preferably at least two longitudinal strings of a ball game racket without substantially coupling the embraced strings with each other.

The present invention relates to a dampening device for ball gamerackets, in particular tennis, squash, racket ball and badmintonrackets, which can be fixed to the strings of the ball game racket.Moreover, the present invention relates to a ball game racket with adampening device of this kind.

Dampening devices which are fixed to the strings of ball game racketsare in principle known. An example for a vibration absorber isdescribed, for example, in AT-C 352 590 and the corresponding U.S. Pat.No. 4,180,265. This vibration absorber is formed such that the twomiddle longitudinal strings are connected to an elastomeric,viscoelastic vibration absorber at the end of the striking surface whichis near the handle or the heart and outside the region of the transversestrings. This vibration absorber is designed to establish aforce-transmitting connection to each of the longitudinal strings to becoupled. According to an embodiment, the vibration absorber thereforehas two spaced-apart bores through which the longitudinal strings arethreaded during the application of the strings to the racket. Accordingto a further embodiment, the vibration absorber has a slot in itscentral region, wherein the vibration absorber is fitted on the desiredneighboring longitudinal strings during application of the strings tothe racket. The length of the slot is smaller than the distance betweenthe strings to be covered. According to a further embodiment, thevibration absorber is essentially S-shaped so that two bearing surfacesfor receiving the longitudinal strings are formed. According to thisembodiment, the vibration absorber can be subsequently fitted on twoneighboring strings of a previously strung racket. The dimension of thevibration absorber should be selected such that the two longitudinalstrings to be coupled are urged toward each other owing to thefitting-on of the vibration absorber.

U.S. Pat. No. 4,732,383 describes a shock and vibration absorber forrackets, which is shaped as a bar and weaved over and under the verticalstrings in a region between the handle and the nearest transversestring. This absorber extends along the entire width of the racket inthis region, wherein the ends are fixed in the spaces between the frameand the nearest longitudinal strings. The bar-shaped absorber iscomposed of a plurality of layers of a shock-and-frequency absorbingmaterial being soft, light and resilient. Also in this dampening devicethe longitudinal strings are coupled by means of the absorber.

Further dampening devices in which the strings are coupled with eachother are disclosed, for example, in U.S. Pat. Nos. 4,776,590,4,190,249, EP-A-0 261 994, EP-A-0 497 561, EP-A-0 642 811,JP-A-03231689, WO-A-88/02271 and WO-A-90/09215. These known dampeningdevices are unsatisfactory with respect to their dampening properties,their fitting-on requirements and/or their relatively complicated andthus expensive production.

It is an object of the present invention to provide an improveddampening device and an improved ball game racket, wherein in particularthe disadvantages of the known devices should be overcome. This objectis achieved with the features of the claims.

In achieving this object, the invention starts out from the basic ideaof constructing a dampening or cushioning device as a preferablylongitudinal base body made of a foam material, so that the dampeningdevice can be fixed to at least one longitudinal string of the ball gameracket by means of a connecting means. Preferably, the dampening deviceis configured such that it can be fixed to at least two, more preferablyfour longitudinal strings of a ball game racket by means of theconnecting means without substantially coupling the embraced stringswith each other.

The base body can be configured as one part so that it forms a ring orloop when embracing the strings, or the base body can consist of severalparts, in particular two parts, wherein the two parts preferably faceeach other and embrace the strings after having been closed.

The connecting means is preferably provided on an entire side of thebase body or on portions thereof. In order to allow the dampening deviceto be reused, the connecting means can preferably be opened and closedagain. In particular, the connecting means can be configured as anadhesive layer, preferably as a releasable and/or repositionableadhesive layer, wherein the dampening device embraces the strings withits tacky side facing the strings. As an alternative or in additionthereto, the connecting means can be formed as a mechanical closure, forexample in the form of a hook and loop closure. In this connection, itis particularly preferred to configure the closure elements of themechanical connecting means such that they can engage themselves (e.g.mushroom-shaped hook elements). However, it is also possible to providea first element of the mechanical closure at a portion or a base bodyelement of the base body and a second element of the mechanical closureat a second portion or second base body element, wherein the two closureelements can be engaged with each other. For example, a first portion orbase body element could comprise hooks which can be engaged with loopsof the second portion or base body element.

The foam material of the base body is preferably an open-cell orclosed-cell foam. The foam material of the base material preferably hasa bulk density between 10 and 1000 kg/m³ and more preferably between 100and 500 kg/m³. The thermal conductivity of the foam material preferablylies between 0.03 and 0.05 W/mK. Examples of foam materials which aresuitable for being used as the base body of the dampening device of thepresent invention are, i.a., polystyrene, polyvinyl chloride,polyethylene, polyurethane, urea formaldehyde, phenol formaldehyde,epoxy resin and silicone.

The ball game racket of the present invention, in particular tennis,squash, racket ball or badminton racket, has strings comprisinglongitudinal and transverse strings, wherein the dampening device isfixed to at least one, preferably at least two, more preferably four ofthe longitudinal strings. The embraced strains are not substantiallycoupled with each other. The dampening device is preferably fixed to thelongitudinal strings in a region outside the transverse strings, inparticular in a region between the heart region of the ball game racketand the transverse string being closest to the heart region. Accordingto a preferred embodiment of the ball game racket of the presentinvention, the dampening device is provided in the region of the longestlongitudinal string and/or embraces four neighboring longitudinalstrings. The dampening device embraces the longitudinal stringspreferably in a relatively loose manner.

A ball game racket comprising the dampening device of the presentinvention surprisingly exhibits particularly advantageous dampening orattenuation characteristics being pleasant to the player, can be handledvery well and is vibration-preventing, wherein at the same time theracket makes a pleasant sound although in its simplest embodiment thedampening device is fixed to only one single string. These properties ofthe ball game racket of the present invention come to light even moreadvantageously if the dampening device is provided on at least two,preferably on four of the longitudinal strings of the racket. Moreover,the dampening device is constructed simple manner so that the productioncosts are low and the dampening device can be fixed easily.

Preferred embodiments of the dampening device according to the inventionand the ball game racket according to the invention are exemplarilydescribed in the following on the basis of the drawings in which

FIG. 1 is a partial top view of a ball game racket according to theinvention with a dampening device according to the invention fixed tothe strings;

FIG. 2 a is a cross-sectional view along the line II-II of FIG. 1 inwhich a first way of fixing the dampening device according to theinvention is shown;

FIG. 2 b is a cross-sectional view along the line II-II of FIG. 1 inwhich a second way of fixing the dampening device according to theinvention is shown;

FIGS. 3 a and 3 b are schematic representations of a first embodiment ofthe dampening device according to the invention;

FIGS. 4 a and 4 b are schematic representations of a second embodimentof the dampening device according to the invention;

FIGS. 5 a and 5 b are schematic representations of a third embodiment ofthe dampening device according to the invention;

FIGS. 6 a and 6 b are schematic representations of a fourth embodimentof the dampening device according to the invention.

FIG. 1 schematically shows a portion of the ball game racket accordingto the invention. The ball game racket essentially comprises a frame 2as well as strings comprising longitudinal strings 4 and transversestrings 6. The frame 2 of the racket in principle comprises a handleportion (not shown) and a head portion (not shown either) with a heartportion therebetween. A part of the heart portion is suggested by theconnecting web 8 shown in FIG. 1.

At least one dampening device 10 according to the invention is providedin the portion between the lowermost transverse string 6* and the heartportion 8 of the racket. According to the representation in FIG. 1, thedampening device 10 is fixed to four neighboring longitudinal strings 4of the ball game racket strings.

In FIGS. 2 a and 2 b, the dampening device 10 is wound around fourneighboring longitudinal strings 4. The longitudinal strings 4 aresubstantially not coupled with each other by the dampening deviceaccording to the invention. As shown in FIG. 2 a, the dampening device10 according to the invention embraces the longitudinal strings 4,wherein in the area between the individual longitudinal strings 4, thedampening device leaves open a gap-shaped passage 12, i.e. the twoopposite portions of the dampening device 10 do not contact each other.In contrast thereto, in the embodiment schematically shown in FIG. 2 b,the dampening device is arranged at the longitudinal strings 4 of theracket in such a manner that at least between some of the longitudinalstrings the opposite portions of the dampening device contact each otherat contact points 14 and are connected with each other at these points;nevertheless, the longitudinal strings 4 are not substantially coupledwith each other.

FIGS. 3 a and 3 b show a first basic embodiment of the dampening device10 according to the invention in more detail. The dampening device 10essentially comprises a tape-shaped or elongate base body 16 and aconnecting means 18. The base body 16 is made of a foam material,preferably an open-cell or closed-cell foam. A preferred foam materialhas a bulk density between 10 and 1000 kg/m³, preferably between 100 and500 kg/m³. Moreover, suitable foam materials preferably have a thermalconductivity between 0.03 and 0.05 W/mK. Typically suitable foammaterials are, for example, polystyrene, polyvinyl chloride,polyethylene, polyurethane, urea formaldehyde, phenol formaldehyde,epoxy resin or silicone.

In the embodiment of the dampening device 10 shown in FIG. 3 a, theconnecting means 18 is formed on the base body 16 as a continuousadhesive layer 18. The adhesive layer 18 preferably comprises areleasable and/or repositionable adhesive, i.e. after having beenadhered by means of the adhesive layer 18, the dampening device 10 canbe removed without leaving any essential residual adhesive and, in caseof a repositionable adhesive, it can be adhered again. For example, apressure-sensitive adhesive is suitable for this purpose.

In accordance with a preferred embodiment, a lining material or liner(not shown) is provided on the adhesive layer 18 of the dampening deviceaccording to the invention before the dampening device is fixed to theball game racket in order to cover and protect the adhesive layer 18.

For fixing the dampening device shown in FIG. 3 a to a ball game racket,the adhesive layer 18 is first released, for example by removing theliner. The dampening device is then wound around the desiredlongitudinal strings 4 of the ball game racket in accordance with therepresentations of FIGS. 2 a and 2 b, wherein the adhesive layer 18 isfacing the strings. For closing the dampening device 10 or fixing it atthe racket, either a first end portion 20 of the dampening device 10 isadhered in an overlapping manner on a second end portion 22 of thedampening device by means of the adhesive layer 18 in order to form aflat ring, or the two end portions are adhered to each other by means ofthe adhesive layer 18 in order to form a loop.

FIG. 3 b shows a modification of this first embodiment of the dampeningdevice 10 according to the invention in which the adhesive layer 18 isprovided only on portions, preferably only on the end portion 20 of aside of the base body 16. For fixing the dampening device 10 accordingto FIG. 3 b, one of the end portions, for example the second end portion22, is threaded through a space between two neighboring longitudinalstrings and wound around at least to neighboring longitudinal strings 4in the direction towards the other end portion 20 and connectedtherewith by means of the adhesive layer 18. Similar to the embodimentaccording to FIG. 3 a, there are in principle two possibilities. Theadhesive layer 18 is either fixed to the outer side or the inner side ofits opposite end portion 22. In case the end portion 20 is fixed to theouter side, a flat ring is formed in accordance with the representationsshown in FIGS. 2 a and 2 b, while when fixing the adhesive layer 18 tothe inner side of the opposite end 22, a loop is formed in accordancewith the dashed variant of FIG. 3 b, wherein the longitudinal strings 4are embraced by the formed loop.

FIGS. 4 a and 4 b show a second basic embodiment of the dampening deviceaccording to the invention, wherein the connecting device is formed as amechanical closure. In particular, the mechanical closure can beconfigured as a so-called hook and loop closure. In the embodiment shownin FIG. 4 a, the mechanical closure is essentially formed of identical,preferably mushroom-shaped hook elements so that they can engage eachother. The hook-shaped closure elements 24 extend either only onportions of or preferably continuously along one side of the base body16. In a similar manner as described above with reference to FIG. 3 band shown by the arrow in FIG. 4 a, the dampening device 10 can beclosed on the longitudinal strings 4 of a ball game racket by forming aloop embracing at least two longitudinal strings 4, as shown in FIG. 4 ain dashed lines. In accordance with the invention, the strings 4embraced by the dampening device 10 are not substantially coupled witheach other.

The modification of the second embodiment of the dampening device 10according to the invention shown in FIG. 4 b in principle corresponds tothat shown in FIG. 4 a, wherein a first portion of the mechanicalclosure is formed of hook-shaped closure elements 24 and a secondportion of the mechanical closure is formed of loops 26. When closingthe dampening device 10, the hooks 24 engage the loops 26 and thusprovide a connecting means. In contrast to the embodiment shown in FIG.4 b, the loops 26 do not necessarily have to be closed loops but theycan also be partial arcs which can be engaged with the hooks 24.

The third basic embodiment of the dampening device 10 according to theinvention shown in FIGS. 5 a and 5 b essentially corresponds to therespective embodiments shown in FIGS. 3 a and 3 b, wherein the base body16 consists of two parts and comprises a first body part 16-1 and asecond body part 16-2. At least one of the base body parts 16-1 or 16-2is provided with a connecting means in the form of an adhesive layer 18.In the shown representation, both base body parts have an adhesive layer18-1 and 18-2. For fixing the dampening device 10 to the longitudinalstrings 4 of a ball game racket in accordance with FIG. 5 a, first thefirst base body part 16-1 is placed on the longitudinal strings 4 sothat its adhesive layer 18-1 faces the longitudinal strings 4, and thenthe second base body part 16-2 is placed with its adhesive layer 18-2 onthe opposite sides of the longitudinal strings and the first base bodypart 16-1, so that the two base body parts 16-1 and 16-2 can beconnected with each other at least in the area of their end portions 20and 22 by means of the adhesive layer 18-1 and/or 18-2. A connection inthe intermediate area between the strings 4 is also possible. The secondbase body part 16-2 does not necessarily have to have an adhesive layer18-2.

The modification of the third embodiment shown in FIG. 5 b essentiallycorresponds to that shown in FIG. 5 a, wherein the first base body part16-1, for example, has an adhesive layer 18-1 on its end portion 22 andthe second base body part 16-2 has an adhesive layer 18-2 on its endportion 20. The dampening device 10 according to FIG. 5 b is fixed inthe same manner as described with reference to FIG. 5 a.

FIG. 6 a shows a fourth basic embodiment of the dampening device 10according to the invention; it consists of a first base body part 16-1and a second base body part 16-2 and a connecting means in the form ofengageable hook elements 24 corresponding to the description of theembodiment shown in FIG. 4 a. The dampening device 10 according to FIG.6 a is fixed to the longitudinal strings of a ball game racket in amanner similar to that described in connection with FIGS. 5 a and 5 b,wherein the hook elements 24-1 of the first base body part 16-1 areengaged with the hook elements 24-2 of the second base body part 16-2.

The embodiment shown in FIG. 6 b is a modification of the fourthembodiment of the dampening device according to the invention as shownin FIG. 6 a, wherein the mechanical closure is formed of hook elements24 and loop elements 26, as already described with reference to theembodiment shown in FIG. 4 b. However, in this embodiment the dampeningdevice according to the invention comprises a base body consisting of afirst base body part 16-1 with hook elements 24 and a second base bodypart 16-2 with loops 26. The dampening device according to FIG. 6 b isfixed in the same way as described above, namely by engaging the twoelements of the connecting means thereby enclosing the longitudinalstrings 4.

As a modification of the embodiments of the shown dampening devicecomprising a base body having a rectangular cross-section, thecross-section of the base body can also have different shapes. Forexample, the base body could have a triangular, semi-circular ortrapezoidal cross-section. Moreover, the base body does not have to betape-shaped or elongate but it can also have different shapes (in thetop view), for example square, circular, figure-eight-shaped, oval, etc.

Both the mechanical connecting means and the connecting means formed bythe adhesive layer(s) can be provided on portions of or on a completeside of the base body or base body parts.

The dampening device according to the invention is advantageous in thatit can be produced and fixed to the strings of a ball game racketeasily, wherein it is preferably reusable and exhibits particularlyadvantageous dampening or absorption characteristics. Moreover, thesound caused when the ball is struck by means of the ball game racket isinfluenced in a particularly advantageous manner in that a relativelydull or sonorous “plong” is caused.

1. A dampening device for ball game rackets comprising a base body madeof foam material and a connector formed such that the dampening devicecan be fixed to at least two longitudinal strings of a ball game racket,the dampening device being configured to embrace opposing sides of eachof the at least two longitudinal strings without fully enclosing each ofthe at least two longitudinal strings, and the base body comprising twoparts, wherein the two parts can be fixed opposite each other in such away that the at least two longitudinal strings are enclosed between thetwo parts.
 2. The dampening device according to claim 1, which isconfigured such that the dampening device can be fixed to fourlongitudinal strings of the racket.
 3. The dampening device according toclaim 1, wherein the base body is elongate or tape-shaped.
 4. Thedampening device according to claim 1, wherein the connector is providedon a side of the base body.
 5. The dampening device according to claim1, which is reusable in that the connector can be reopened.
 6. Thedampening device according to claim 1, wherein the connector is formedas an adhesive layer provided on the base body.
 7. The dampening deviceaccording to claim 6, wherein the adhesive layer is releasable,repositionable, or releasable and repositionable.
 8. The dampeningdevice according to claim 1, wherein the connector is formed as amechanical closure.
 9. The dampening device according to claim 8,wherein a first base body part comprises a first part of the mechanicalclosure and a second base body part comprises a second part of themechanical closure which are engageable with each other.
 10. Thedampening device according to claim 8, wherein the mechanical closureextends essentially along the entire length of the base body andcomprises essentially identical hook elements that are engageable witheach other.
 11. The dampening device according to claim 8, whereinmechanical closure is a hook and loop closure.
 12. The dampening deviceaccording to claim 1, wherein at least one of the base body partscomprises an adhesive layer for a connection with the other base bodypart.
 13. The dampening device according to claim 1, wherein the foammaterial of the base body is made of open-cell or closed-cell foam. 14.The dampening device according to claim 1, wherein the foam material ofthe base body has a bulk density between 10 and 1000 kg/m³.
 15. Thedampening device according to claim 14, wherein the foam material of thebase body has a bulk density between 100 and 500 kg/m³.
 16. Thedampening device according to claim 1, wherein the foam material of thebase body has a thermal conductivity between 0.03 and 0.05 W/mK.
 17. Thedampening device according to claim 1, wherein the foam material of thebase body comprises a material selected from the group consisting ofpolystyrene, polyvinyl chloride, polyethylene, polyurethane, ureaformaldehyde, phenol formaldehyde, epoxy resin and silicone.
 18. A ballgame racket comprising at least one dampening device according to claim1, wherein the ball game racket has strings comprising the at least twolongitudinal strings and transverse strings and wherein the dampeningdevice is fixed to the at least two of the longitudinal strings andembraces them relatively loosely.
 19. The ball game racket according toclaim 18, wherein the dampening device is fixed to the longitudinalstrings in an area outside the transverse strings.
 20. The ball gameracket according to claim 18, wherein the dampening device is fixed tothe longitudinal strings in an area between the heart portion of theracket and the transverse string closest to the heart portion.
 21. Theball game racket according to claim 18, wherein the dampening device isprovided in the area of the longitudinal strings that are longest. 22.The ball game racket according to claim 18, wherein the dampening deviceis fixed to at least two neighboring longitudinal strings.
 23. The ballgame racket according to claim 18, wherein the dampening device is fixedto four neighboring longitudinal strings.